Limits...
Transient laminin beta 1a Induction Defines the Wound Epidermis during Zebrafish Fin Regeneration.

Chen CH, Merriman AF, Savage J, Willer J, Wahlig T, Katsanis N, Yin VP, Poss KD - PLoS Genet. (2015)

Bottom Line: Here, we performed a forward genetic screen for mutations that impair this process in amputated zebrafish fins.These events facilitate expression of the morphogenetic factors shha and lef1, basolateral positioning of phosphorylated Igf1r, patterning of new osteoblasts, and regeneration of bone.By contrast, lamb1a function is dispensable for juvenile body growth, homeostatic adult tissue maintenance, repair of split fins, or renewal of genetically ablated osteoblasts. fgf20a mutations or transgenic Fgf receptor inhibition disrupt lamb1a expression, linking a central growth factor to epithelial maturation during regeneration.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology and Howard Hughes Medical Institute, Duke University School of Medicine, Durham, North Carolina, United States of America.

ABSTRACT
The first critical stage in salamander or teleost appendage regeneration is creation of a specialized epidermis that instructs growth from underlying stump tissue. Here, we performed a forward genetic screen for mutations that impair this process in amputated zebrafish fins. Positional cloning and complementation assays identified a temperature-sensitive allele of the ECM component laminin beta 1a (lamb1a) that blocks fin regeneration. lamb1a, but not its paralog lamb1b, is sharply induced in a subset of epithelial cells after fin amputation, where it is required to establish and maintain a polarized basal epithelial cell layer. These events facilitate expression of the morphogenetic factors shha and lef1, basolateral positioning of phosphorylated Igf1r, patterning of new osteoblasts, and regeneration of bone. By contrast, lamb1a function is dispensable for juvenile body growth, homeostatic adult tissue maintenance, repair of split fins, or renewal of genetically ablated osteoblasts. fgf20a mutations or transgenic Fgf receptor inhibition disrupt lamb1a expression, linking a central growth factor to epithelial maturation during regeneration. Our findings reveal transient induction of lamb1a in epithelial cells as a key, growth factor-guided step in formation of a signaling-competent regeneration epidermis.

No MeSH data available.


Related in: MedlinePlus

lamb1a is required for juvenile fin growth but not body growth.(A) Juvenile sde1 animals, after incubation from 4 to 6 weeks post-fertilization (wpf) at 33°C, acquire degraded fins. Scale bars, 2 mm. (B) sde1 mutations have minimal impact on juvenile outgrowth. Body length was measured from the tip of the snout to the base of caudal fin. (C) RT-qPCR analysis indicates that both lamb1a and lamb1b are induced in fin tissue during juvenile outgrowth. qPCR results were normalized to rpl13a and to the basal expression of lamb1a/lamb1b in adult uninjured fins (n = 4; mean ± SEM). (D) Antibody staining for Laminin expression in juvenile fins. Laminin protein in longitudinal sections of fins is localized to the basal side of the epitheilum in sde1/+ animals, but becomes mislocalized in sde1 mutants.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4549328&req=5

pgen.1005437.g005: lamb1a is required for juvenile fin growth but not body growth.(A) Juvenile sde1 animals, after incubation from 4 to 6 weeks post-fertilization (wpf) at 33°C, acquire degraded fins. Scale bars, 2 mm. (B) sde1 mutations have minimal impact on juvenile outgrowth. Body length was measured from the tip of the snout to the base of caudal fin. (C) RT-qPCR analysis indicates that both lamb1a and lamb1b are induced in fin tissue during juvenile outgrowth. qPCR results were normalized to rpl13a and to the basal expression of lamb1a/lamb1b in adult uninjured fins (n = 4; mean ± SEM). (D) Antibody staining for Laminin expression in juvenile fins. Laminin protein in longitudinal sections of fins is localized to the basal side of the epitheilum in sde1/+ animals, but becomes mislocalized in sde1 mutants.

Mentions: To examine lamb1a functions during juvenile growth, we shifted sde1 animals from 25°C to 33°C at 4 weeks post fertilization (wpf), after zebrafish reach their juvenile stage. After 2 weeks at 33°C, all 6 wpf sde1 animals (10/10) had noticeably degraded fins, whereas majority of sde1/+ siblings displayed no noticeable fin phenotypes (12/14). Interestingly, this temperature shift did not grossly affect the body length of sde1 juvenile animals (Fig 5B). Using specific qPCR probes targeting lamb1a and lamb1b sequences, we found that both lamb1a and lamb1b mRNA levels were higher in juvenile fins than in adult uninjured fins (Fig 5C). These results indicate that lamb1a is required for juvenile fin growth and/or tissue maintenance, but is dispensable for organismal growth at the juvenile stage.


Transient laminin beta 1a Induction Defines the Wound Epidermis during Zebrafish Fin Regeneration.

Chen CH, Merriman AF, Savage J, Willer J, Wahlig T, Katsanis N, Yin VP, Poss KD - PLoS Genet. (2015)

lamb1a is required for juvenile fin growth but not body growth.(A) Juvenile sde1 animals, after incubation from 4 to 6 weeks post-fertilization (wpf) at 33°C, acquire degraded fins. Scale bars, 2 mm. (B) sde1 mutations have minimal impact on juvenile outgrowth. Body length was measured from the tip of the snout to the base of caudal fin. (C) RT-qPCR analysis indicates that both lamb1a and lamb1b are induced in fin tissue during juvenile outgrowth. qPCR results were normalized to rpl13a and to the basal expression of lamb1a/lamb1b in adult uninjured fins (n = 4; mean ± SEM). (D) Antibody staining for Laminin expression in juvenile fins. Laminin protein in longitudinal sections of fins is localized to the basal side of the epitheilum in sde1/+ animals, but becomes mislocalized in sde1 mutants.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4549328&req=5

pgen.1005437.g005: lamb1a is required for juvenile fin growth but not body growth.(A) Juvenile sde1 animals, after incubation from 4 to 6 weeks post-fertilization (wpf) at 33°C, acquire degraded fins. Scale bars, 2 mm. (B) sde1 mutations have minimal impact on juvenile outgrowth. Body length was measured from the tip of the snout to the base of caudal fin. (C) RT-qPCR analysis indicates that both lamb1a and lamb1b are induced in fin tissue during juvenile outgrowth. qPCR results were normalized to rpl13a and to the basal expression of lamb1a/lamb1b in adult uninjured fins (n = 4; mean ± SEM). (D) Antibody staining for Laminin expression in juvenile fins. Laminin protein in longitudinal sections of fins is localized to the basal side of the epitheilum in sde1/+ animals, but becomes mislocalized in sde1 mutants.
Mentions: To examine lamb1a functions during juvenile growth, we shifted sde1 animals from 25°C to 33°C at 4 weeks post fertilization (wpf), after zebrafish reach their juvenile stage. After 2 weeks at 33°C, all 6 wpf sde1 animals (10/10) had noticeably degraded fins, whereas majority of sde1/+ siblings displayed no noticeable fin phenotypes (12/14). Interestingly, this temperature shift did not grossly affect the body length of sde1 juvenile animals (Fig 5B). Using specific qPCR probes targeting lamb1a and lamb1b sequences, we found that both lamb1a and lamb1b mRNA levels were higher in juvenile fins than in adult uninjured fins (Fig 5C). These results indicate that lamb1a is required for juvenile fin growth and/or tissue maintenance, but is dispensable for organismal growth at the juvenile stage.

Bottom Line: Here, we performed a forward genetic screen for mutations that impair this process in amputated zebrafish fins.These events facilitate expression of the morphogenetic factors shha and lef1, basolateral positioning of phosphorylated Igf1r, patterning of new osteoblasts, and regeneration of bone.By contrast, lamb1a function is dispensable for juvenile body growth, homeostatic adult tissue maintenance, repair of split fins, or renewal of genetically ablated osteoblasts. fgf20a mutations or transgenic Fgf receptor inhibition disrupt lamb1a expression, linking a central growth factor to epithelial maturation during regeneration.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology and Howard Hughes Medical Institute, Duke University School of Medicine, Durham, North Carolina, United States of America.

ABSTRACT
The first critical stage in salamander or teleost appendage regeneration is creation of a specialized epidermis that instructs growth from underlying stump tissue. Here, we performed a forward genetic screen for mutations that impair this process in amputated zebrafish fins. Positional cloning and complementation assays identified a temperature-sensitive allele of the ECM component laminin beta 1a (lamb1a) that blocks fin regeneration. lamb1a, but not its paralog lamb1b, is sharply induced in a subset of epithelial cells after fin amputation, where it is required to establish and maintain a polarized basal epithelial cell layer. These events facilitate expression of the morphogenetic factors shha and lef1, basolateral positioning of phosphorylated Igf1r, patterning of new osteoblasts, and regeneration of bone. By contrast, lamb1a function is dispensable for juvenile body growth, homeostatic adult tissue maintenance, repair of split fins, or renewal of genetically ablated osteoblasts. fgf20a mutations or transgenic Fgf receptor inhibition disrupt lamb1a expression, linking a central growth factor to epithelial maturation during regeneration. Our findings reveal transient induction of lamb1a in epithelial cells as a key, growth factor-guided step in formation of a signaling-competent regeneration epidermis.

No MeSH data available.


Related in: MedlinePlus